1. Field of the Invention
The present invention relates to a cable modem that exchanges information by using a CATV network as an information transfer medium.
2. Description of the Prior Art
An example of a conventional cable modem is shown in FIG. 9. This cable modem 81 is, on the one hand, connected by way of a 75 Ω coaxial cable 82 to a CATV station (head end) of a CATV network (not shown), and, on the other hand, connected by way of cables 84a, 84b, . . . , such as a LAN cable and a USB (universal serial bus) cable, to an information processing terminals 83a, 83b, . . . , such as personal computers (this system will be referred to as conventional system 1). In FIG. 9, reference numeral 91 represents a set-top box connected to an RF coaxial cable 100, and reference numeral 92 represents a television monitor connected to the set-top box. Reference symbol LO represents a living room, and reference symbols L1 and L2 represent other rooms separate therefrom.
On the other hand, for example, Japanese Patent Application Laid-Open No. H10-234028 discloses a cable modem (CATV home unit) provided with a CATV data transmission/reception unit and a wireless LAN unit. Here, the CATV data transmission/reception unit is connected by way of a CATV cable to a CATV network, and is connected to individual information processing terminals through wireless communication by the wireless LAN unit (this system will be referred to as conventional system 2).
However, with the cable modem of conventional system 1 described above, which is based on wired communication, the connection between the cable modem 81 and information processing terminals 83a, 83b, . . . , such as personal computers, requires installation of cables 84a, 84b, . . . , such as a LAN cable and a USB cable. In particular in cases where the cable modem 81 is installed in a room separate from the rooms in which the information processing terminals 83a, 83b, . . . are installed, installation of the cables requires large-scale work.
On the other hand, switching from wired communication as employed by conventional system 1 described above to wireless communication as employed by conventional system 2 described above requires replacement of the cable modem itself, and thus requires extra costs.